Medical catheter assembly including a balloon bolster

ABSTRACT

A medical catheter assembly including either a reinforced balloon bolster or the combination of a balloon bolster and a wire-basket bolster. According to one embodiment, the medical catheter assembly is a low-profile replacement PEG device comprising a feeding tube, an external bolster, an end cap and an internal bolster. The internal bolster comprises a first expandable structure and a second expandable structure. In one embodiment, the first expandable structure is a balloon and the second expandable structure comprises reinforcing members. In another embodiment, the first expandable structure is a balloon and the second expandable structure is a wire basket bolster. The feeding tube has a feeding lumen and an inflation lumen, extending parallel longitudinally. The external bolster is fixed to the external end of the feeding tube and has a feeding lumen aligned with that of the tube and an inflation lumen aligned with that of the tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit under 35 U.S.C. 119(e) ofU.S. Provisional Patent Application Ser. No. 60/853,136, filed Oct. 20,2006, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to medical catheter assembliesof the type including a medical catheter and a balloon bolster disposedat the internal end of the medical catheter for retaining said end ofsaid medical catheter within a patient and relates more particularly toa novel such medical catheter assembly.

Certain patients are unable to take food and/or medications transorallydue to an inability to swallow. Such an inability to swallow may be dueto a variety of reasons, such as esophageal cancer, neurologicalimpairment and the like. Although the intravenous administration of foodand/or medications to such patients may be a viable short-term approach,it is not well-suited for the long-term. Accordingly, the most commonapproach to the long-term feeding of such patients involves gastrostomy,i.e., the creation of a feeding tract or stoma between the stomach andthe upper abdominal wall. (A less common approach involves jejunostomy,i.e., the creating of a feeding tract or stoma leading into thepatient's jejunum.) Feeding is then typically performed by administeringfood through a catheter or feeding tube that has been inserted into thefeeding tract, with one end of the feeding tube extending into thestomach and being retained therein by an internal anchor or bolster andthe other end of the feeding tube extending through the abdominal walland terminating outside the patient.

Although gastrostomies were first performed surgically, mostgastrostomies are now performed using percutaneous endoscopy and resultin the implantation in the patient of a feeding tube/internal bolsterassembly (said feeding tube/internal bolster assembly also commonlyreferred to as a percutaneous endoscopy gastrostomy (PEG) device). Twoof the more common percutaneous endoscopic techniques for implanting aPEG device in a patient are “the push method” (also known as “theSacks-Vine method”) and “the pull method” (also known as “theGauderer-Ponsky method”). Information regarding the foregoing twomethods may be found in the following patents, all of which areincorporated herein by reference: U.S. Pat. No. 5,391,159, inventorsHirsch et al., which issued Feb. 21, 1995; U.S. Pat. No. 5,167,627,inventors Clegg et al., which issued Dec. 1, 1992; U.S. Pat. No.5,112,310, inventor Grobe, which issued May 12, 1992; U.S. Pat. No.4,900,306, inventors Quinn et al., which issued Feb. 13, 1990; and U.S.Pat. No. 4,861,334, inventor Nawaz, which issued Aug. 29, 1989.

According to the push method, one end of an endoscope is intubated(i.e., inserted) into a patient's mouth and is passed through theesophagus into the stomach. After distension of the stomach byinflation, an entry site on the abdomen is identified using theendoscope for transillumination, and an incision is made by passing thetip of a needle coupled to an outer cannula through the abdominal andstomach walls and into the stomach. One end of the outer cannula remainsoutside of the body and acts as a stop to limit insertion of the needleand outer cannula into the stomach. A snare is inserted into the stomachvia the endoscope and is looped over the inserted end of the needle. Thesnare is then “walked” up the needle until the outer cannula is snared.The snared cannula is then pulled externally to tack the cannula to thestomach and, in turn, to secure the stomach wall to the abdominal wall.The needle is then removed from the patient while keeping the cannula inplace. A first end of a flexible guidewire (also known in the art as a“pushwire”) is then passed through the cannula and into the stomachwhere it is grasped by the snare, the second end of the guidewireremaining external to the patient. The endoscope and the snare are thenwithdrawn from the mouth of the patient to deliver the first end of theguidewire.

A push-type catheter implanting assembly is then inserted over the firstend of the guidewire and is pushed over the guidewire towards its secondend. The push-type catheter implanting assembly typically comprises agastrostomy feeding tube, the gastrostomy feeding tube having adome-shaped internal bolster disposed at its trailing end and having atubular dilator serially connected to its leading end. The gastrostomyfeeding tube and the internal bolster are typically made of a soft,biocompatible material, like silicone rubber, and typically form aunitary structure. The dilator, which tapers in outer diameter from itstrailing end to its leading end, is typically made of polyethylene or alike material which is stiffer than silicone but which still possessessome flexibility. Advancement of the push-type catheter implantingassembly over the guidewire continues until the front end of the dilatorreaches the cannula and pushes the cannula out through the abdominalwall of the patient. The front end of the dilator is then pulled throughthe abdominal wall until the front end of the gastrostomy feeding tubeemerges from the abdomen and, thereafter, the internal bolster at therear end of the gastrostomy feeding tube engages the stomach wall. Theguidewire is then removed from the patient. The clinician thenre-intubates the patient with the endoscope and uses an optical channelin the endoscope to inspect whether the internal bolster is properlyseated in the stomach.

If the internal bolster is properly placed against the stomach wall, alength of the externally-extending portion of the implanted gastrostomyfeeding tube is then typically cut and removed from the implanted tubeto reduce the externally-extending portion of the tube to a desiredlength (typically about 4-6 inches). (The removal of the leading end ofthe gastrostomy feeding tube also results in the removal of the dilator,which is connected thereto.) An external bolster is typically secured tothe remaining externally-extending portion of the feeding tube to engagethe abdomen in such a way as to prevent longitudinal movement of thefeeding tube into the stomach. Additionally, a “Y-port” adapter istypically attached to the external end of the feeding tube, the Y-portadapter being adapted to receive a pair of connector tips through whichfood and/or medications may be dispensed. In addition, a detachablelocking clip is typically secured to the implanted feeding tube at apoint between the external bolster and the Y-port adapter to preventgastric fluids from escaping through the proximal end of the feedingtube when the feeding tube is not in use.

The pull method is similar in some respects to the above-described pushmethod, the pull method differing from the push method in that, afterthe cannula is snared and the needle is removed therefrom, a loopedfirst end of a suture (also known in the art as a “pullwire”) isinserted through the cannula and into the stomach where it is grasped bythe snare, the second end of the suture remaining external to thepatient. The endoscope and the snare are then withdrawn from the mouthof the patient to deliver the first end of the suture. The first end ofthe suture is then coupled to the leading end of a pull-type catheterimplanting assembly, the pull-type catheter implanting assemblytypically comprising a gastrostomy feeding tube having an internalbolster integrally formed at its trailing end and a plastic fittingattached to its leading end. The plastic fitting typically has a barbedrear portion mounted within the leading end of the feeding tube and aconical front portion that serves as a dilator, said conical frontportion tapering in diameter from the leading end of the feeding tube toa front tip. A wire loop is fixed to the front tip of the plasticfitting, the first end of the suture being tied to the wire loop. Usingthe second end of the suture, the pull-type catheter implanting assemblyis then pulled retrograde through the patient until the gastrostomyfeeding tube emerges from the abdomen of the patient and the internalbolster engages the stomach wall of the patient. Next, as is the case inthe push method, the clinician then re-intubates the patient with theendoscope in order to visually inspect the placement of the internalbolster within the stomach. If the bolster is properly seated in thestomach, the externally-extending portion of the implanted gastrostomyfeeding tube is then typically cut to a desired length and one or moreof an external bolster, a Y-port and a clamp are attached to the feedingtube.

In addition to the above-described endoscopic techniques for implantingPEG devices, there also exist direct percutaneous techniques.

Although PEG devices of the type described above work well for theirintended purpose, such devices tend to wear out over time and/or do notsuit the lifestyle of more active patients as the several inches lengthof tubing that extends externally can be unwieldy, difficult to concealand susceptible to being inadvertently pulled on. Consequently, varioustypes of replacement PEG devices have been devised to replaceinitially-implanted PEG devices. Some of these replacement PEG devicesare often referred to as “low-profile” in that they are considerablymore compact externally than the above-described initially-implanted PEGdevices and, thus, are particularly well-suited for active patients.Other replacement PEG devices are often referred to as“standard-profile” in that they are less compact than “low-profile” PEGdevices.

Many replacement PEG devices, whether “low-profile” or“standard-profile,” use an inflatable balloon as an internal bolster toretain the inserted end of the feeding tube within a patient's stomach.To implant such a device in a patient, the end of the tube carrying theballoon is inserted through the stoma with the inflatable balloon in adeflated state, and the balloon is then inflated, typically using aneedle-less syringe or the like. The balloon may be inflated with airor, more preferably, is inflated with a sterile, biologically compatibleliquid, such as a saline solution. To remove the implanted device from apatient, the balloon is deflated, and the tube is then withdrawn fromthe stoma. Examples of replacement PEG devices having an inflatableballoon bolster are disclosed in the following U.S. patents andpublished U.S. patent applications, all of which are incorporated byreference: U.S. Pat. No. 4,685,901, inventor Parks, which issued Aug.11, 1987; U.S. Pat. No. 5,342,321, inventor Potter, which issued Aug.30, 1994; U.S. Pat. No. 5,836,924, inventors Kelliher et al., whichissued Nov. 17, 1998; U.S. Pat. No. 5,860,952, inventor Quinn, whichissued Jan. 19, 1999; U.S. Pat. No. 5,997,503, inventors Willis et al.,which issued Dec. 7, 1999; U.S. Pat. No. 6,077,243, inventor Quinn,which issued Jun. 20, 2000; U.S. Pat. No. 6,019,746, inventors Picha etal., which issued Feb. 1, 2000; U.S. Pat. No. 6,264,631, inventorsWillis et al., which issued Jul. 24, 2001; U.S. Pat. No. 6,916,307,inventors Willis et al., which issued Jul. 12, 2005; and U.S. PatentApplication Publication No. US 2004/0147874, inventors Kliem et al.,which was published Jul. 29, 2004.

One shortcoming of PEG devices having a balloon bolster is that theballoon bolster has a tendency to fail over time. As can be appreciated,failure of the bolster can lead to the device falling out of thepatient, an occurrence that is not desired.

SUMMARY OF THE INVENTION

In one embodiment, the invention provides a novel medical catheterassembly of the type having a balloon bolster.

In another embodiment, the invention provides a medical catheterassembly as described above that overcomes at least some of theshortcomings in connection with existing medical catheter assemblies ofthe type having a balloon bolster.

Therefore, according to one aspect of the invention, there is provided amedical catheter assembly, said medical catheter assembly comprising (a)a medical catheter; and (b) an expandable bolster disposed at a firstend of said medical catheter, said expandable bolster comprising aribbed or reinforced balloon. The ribbed or reinforced balloon maycomprise a flexible sleeve having embedded therein at least one of thefollowing: at least one linear reinforcing stay, at least onecircumferential reinforcing member, at least one helical reinforcingmember and an expandable wire mesh tube.

According to another aspect of the invention, there is provided amedical catheter assembly, said medical catheter assembly comprising (a)a medical catheter; (b) a first expandable bolster disposed at a firstend of said medical catheter; and (c) a second expandable bolsterdisposed at said first end of said medical catheter. In one embodiment,the first expandable bolster may be a balloon bolster, and the secondexpandable bolster may be a wire-basket bolster, the wire-basket bolsterbeing disposed within the balloon bolster.

According to yet another aspect of the invention, there is provided amethod of securing a device, the method comprising actuating a firstbolster and actuating a second bolster wherein the second bolster servesto maintain security upon failure of the first bolster.

For purposes of the present specification, various relational terms like“top,” “bottom,” “internal,” “external,” “proximal” and “distal” areused to describe the present invention when said invention is positionedin or viewed from a given orientation. It is to be understood that, byaltering the orientation of the invention, certain relational terms mayneed to be adjusted accordingly.

Additional objects, features, aspects and advantages of the presentinvention will be set forth, in part, in the description which followsand, in part, will be obvious from the description or may be learned bypractice of the invention. In the description, reference is made to theaccompanying drawings which form a part thereof and in which is shown byway of illustration specific embodiments for practicing the invention.These embodiments will be described in sufficient detail to enable thoseskilled in the art to practice the invention, and it is to be understoodthat other embodiments may be utilized and that structural changes maybe made without departing from the scope of the invention. The followingdetailed description is, therefore, not to be taken in a limiting sense.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are hereby incorporated into andconstitute a part of this specification, illustrate preferredembodiments of the invention and, together with the description, serveto explain the principles of the invention. In the drawings wherein likereference numerals represent like parts:

FIG. 1 is a section view of a first embodiment of a medical catheterassembly constructed according to the teachings of the presentinvention, the medical catheter assembly including an internal bolsterthat is shown in an unexpanded state;

FIG. 2 is a section view of the medical catheter assembly of FIG. 1, theinternal bolster being shown in an unexpanded state;

FIG. 3 is a side view, broken away in part, of the medical catheterassembly of FIG. 1, the internal bolster being shown in an expandedstate;

FIG. 4 is a section view of a first alternate internal bolster for usewith the medical catheter assembly of FIG. 1;

FIG. 5 is a side view, broken away in part, of a second alternateinternal bolster for use with the medical catheter assembly of FIG. 1;

FIG. 6 is a side view, broken away in part, of a third alternateinternal bolster for use with the medical catheter assembly of FIG. 1;

FIG. 7 is a side view of a second embodiment of a medical catheterassembly constructed according to the teachings of the presentinvention;

FIG. 8 is a fragmentary perspective view of the medical catheterassembly of FIG. 7, with each of the balloon bolster and the wire basketbolster of the medical catheter assembly being shown in an unexpandedstate;

FIG. 9 is a fragmentary section view of the medical catheter assembly ofFIG. 7, with each of the balloon bolster and the wire basket bolster ofthe medical catheter assembly being shown in an unexpanded state; and

FIG. 10 is a fragmentary section view of the medical catheter assemblyof FIG. 7, with each of the balloon bolster and the wire basket bolsterof the medical catheter assembly being shown in an expanded state.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to FIGS. 1 through 3, there are shown various views of afirst embodiment of a medical catheter assembly constructed according tothe teachings of the invention, said medical catheter assembly beingrepresented generally by reference numeral 11.

Assembly 11, which, in the present embodiment, may be a low-profilereplacement PEG device, may comprise a feeding tube 13, an externalbolster 15, an end cap 17 and an internal bolster 19.

Feeding tube 13 may be an elongated, flexible, tubular member,comprising a suitable medical grade silicone, polyurethane or any othersuitably flexible biocompatible polymer or structure (such as a woventube or the like). Feeding tube 13 may be shaped to include an internalend 21, an external end 23, and a pair of longitudinal lumina 25-1 and25-2, lumina 25-1 and 25-2 extending in a parallel fashion from internalend 21 to external end 23. Lumen 25-1 may be considerably greater indiameter than lumen 25-2, and as will become apparent below, lumen 25-1may be used to convey food and/or medications to a patient whereas lumen25-2 may be used to convey fluids to and from internal bolster 19 forits inflation and deflation, respectively.

External bolster 15, which in some embodiments may be fixedly mounted onexternal end 23 of feeding tube 13, may be a unitary structure, made ofa suitable medical grade silicone, polyurethane or any other suitablyflexible biocompatible polymer or structure. Bolster 15 may be shaped tocomprise a feeding port 31, an inflation port 33 and a plug 35. Feedingport 31 may include a feeding lumen 37, feeding lumen 37 being alignedwith lumen 25-1 and may be adapted to receive a feeding tip (not shown)of a conventional device used to dispense food and/or medications into aPEG device. An anti-reflux valve 39, which, in the present embodiment,may be in the form of an integrally formed duckbill valve, may bedisposed within lumen 37 and may be appropriately positioned therewithinto be opened by the full insertion of a feeding tip into lumen 37.

Inflation port 33 may include an inflation lumen 41, and inflation lumen41 may be aligned with lumen 25-2 of feeding tube 13. An internal thread43 may project into lumen 41 near the external end of lumen 41 so thatlumen 41 may matingly receive the externally-threaded tip of aneedle-less syringe. A check valve, which, in the present embodiment,may comprise a plunger 45 and a spring 47, may be disposed within lumen41. In the absence of a syringe being inserted into lumen 41, spring 47biases plunger 45 against an apertured wall 49, thereby preventing fluidflow through apertured wall 49. On the other hand, when a syringe isinserted into lumen 41, plunger 45 is displaced by syringe towardsfeeding tube 13 so that fluid is permitted to flow through aperturedwall 49. A plurality of transverse openings 51 may be provided inplunger 45 to permit fluid to flow through plunger 45 as well as throughapertured wall 49. It should be noted that the check valve is notlimited to the foregoing structure and may take the form of any commonlyknown valve including a ball/spring, flapper, duckbill, etc.

Plug 35, which may be tethered to feeding port 31 by a flexible strap53, may be appropriately sized to sealably, yet removably, fit into theexternal end of feeding lumen 37.

End cap 17, which may be a unitary structure made of a suitable medicalgrade silicone, polyurethane or any other suitably flexiblebiocompatible polymer or structure, may be fixedly mounted on internalend 21 of feeding tube 13. End cap 17 may comprise an end wall 55, endwall 55 sealing the internal end of lumen 25-2. A transverse opening 57may be provided in end wall 55, and opening 57 may be aligned with lumen25-1 and matching lumen 25-1 in diameter so that the contents of lumen25-1 may flow freely through the internal end of lumen 25-1.

Internal bolster 19 may comprise a flexible sleeve 61 and a plurality ofreinforcing members 63. Reinforcing members 63 may be embedded withinsleeve 61. Sleeve 61, which may be made of an expandable membrane ormaterial, such as a suitable medical grade silicone, polyurethane or anyother suitably flexible biocompatible polymer or structure, may beappropriately dimensioned to fit tightly over tube 13, with the internalend 65 of sleeve 61 and the external end 67 of sleeve 61 being securelybonded to tube 13 by a suitable adhesive 68 or by melting. Theintermediate portion of sleeve 61, which may not be bonded to tube 13,may lie over an aperture 70 in tube 13, aperture 70 being in fluidcommunication with lumen 25-2. In this manner, sleeve 61 may be expandedlike a conventional balloon bolster by the introduction of fluidspassing from lumen 25-2 through opening 70 and against sleeve 61.Reinforcing members 63, which may be linear ribs or stays made of, forexample, metals, polymeric materials, elastomeric materials orcombinations thereof, may be embedded within sleeve 61, with reinforcingmembers 63 being spaced apart equidistantly and may be oriented parallelto the length of sleeve 61 or at some other angle relative to the lengthof sleeve 61. Alternatively, reinforcing members 63 may becircumferential reinforcements oriented perpendicular to the length ofsleeve 61 or at some other angle relative to the length of sleeve 61.Alternatively, reinforcing members 63 may include a combination oflinear members and circumferential members. (Although two reinforcingmembers 63 are shown in the present embodiment, it can be appreciatedthat there could be as few as one reinforcing member 63 or more than tworeinforcing members 63.)

Internal bolster 19 may be constructed by a process in which sleeve 61and reinforcing members 63 are co-extruded. In such a case, the ends ofreinforcing members 63 may be covered thereafter with additional sleevematerial so that no portion of reinforcing member 63 is exposed.Alternatively, reinforcing members 63 may be sandwiched between twosheets of material that together form sleeve 61.

Reinforcing members 63 may have sufficient flexibility so that, assleeve 61 is expanded or deflated, reinforcing members 63 assume acorresponding shape. However, at the same time, reinforcing members 63may have sufficient rigidity so that, if sleeve 61 is expanded, forexample, with a liquid, and then suffers a pinhole leak or othernon-catastrophic rupture, reinforcing members 63 substantially maintaintheir shape, keeping the internal end of assembly 11 within the patienton a temporary basis and allowing the patient to seek treatment from amedical professional. (Assembly 11 additionally may include some means,such as an indicator in inflation port 33, to indicate an unexpectedloss in inflation pressure in bolster 19.) The medical professional maythen pull on assembly 11 until the withdrawal force exceeds theretention force provided by reinforcing members 63.

To implant assembly 11 in a patient, one may begin with bolster 19 in anunexpanded state (see FIG. 1) and may insert into the patient via anexisting stoma substantially all of assembly 11, except for externalbolster 15. Next, one may connect a needle-less syringe to inflationport 33 and may dispense a fluid (preferably a liquid, such as salinesolution or sterile water) into inflation lumen 41 until inflationbolster 19 is expanded to a desired extent (see FIGS. 2 and 3). One maythen remove the needle-less syringe from inflation port 33.

Once assembly 11 has been implanted in a patient in the above manner,one may deliver food and/or medications to the patient through feedingport 31 in the conventional manner. When feeding port 31 is not in use,one may seal feeding port 31 with plug 35.

To remove assembly 11 from a patient, one may connect a needle-lesssyringe or the like to feeding port 31 and then may withdraw asufficient quantity of fluid from within bolster 19 until bolster 19shrinks to a sufficiently compact size to permit the withdrawal ofassembly 11 from the patient.

It should be understood that, although assembly 11 has been describedherein as a replacement PEG device, assembly 11 is not limited togastric applications nor is it limited to feeding applications.Moreover, assembly 11 is not limited to use as replacement device andmay be used as an initial placement device. Furthermore, assembly 11 maybe modified to be a standard-profile device, instead of a low-profiledevice, without departing from the present invention.

In other embodiments (not shown), bolster 19 may include a multi-layerballoon structure, a second or reinforcing balloon structure locatedinside a first balloon structure, or a balloon structure with areinforcing covering.

Referring now to FIG. 4, there is shown a section view of a firstalternate internal bolster, said first alternate internal bolster beingrepresented by reference numeral 81.

Internal bolster 81, which may be used instead of internal bolster 19with the remainder of assembly 11, is similar in most respects tointernal bolster 19, the principal difference between the two internalbolsters being that internal bolster 81 may include a single helicalreinforcing member 83, instead of a plurality of linear reinforcingmembers 63. Reinforcing member 83 may be similar in structure toreinforcing members 63 or may be made of a metal or polymer wire or acoil.

Referring now to FIG. 5, there is shown a side view, broken away inpart, of a second alternate internal bolster, said second alternateinternal bolster being represented by reference numeral 91.

Internal bolster 91, which may be used instead of internal bolster 19with the remainder of assembly 11, is similar in most respects tointernal bolster 19, the principal difference between the two internalbolsters being that internal bolster 91 may include an expandable wiremesh tube 93 (such as in a balloon-expandable intravascular stent),instead of a plurality of linear reinforcing members 63. This tube maytake many forms including a knitted or laser cut tube, for example, andis not limited to the particular type of tube shown.

Referring now to FIG. 6, there is shown a side view, broken away inpart, of a third alternate internal bolster, said third alternateinternal bolster being represented by reference numeral 95.

Internal bolster 95, which may be used instead of internal bolster 19with the remainder of assembly 11, is similar in most respects tointernal bolster 19, the principal difference between the two internalbolsters being that internal bolster 95 may include a woven, expandablewire mesh tube 97 (such as in a balloon-expandable intravascular stent),instead of a plurality of linear reinforcing members 63.

Referring now to FIGS. 7 through 10, there are shown various views of asecond embodiment of a medical catheter assembly constructed accordingto the teachings of the invention, said medical catheter assembly beingrepresented generally by reference numeral 101.

Assembly 101, which, in the present embodiment, may be astandard-profile replacement PEG device, may comprise a feeding tube103, an external bolster 105, an end cap 107, a balloon bolster 109, awire-basket bolster 111 (seen best in FIGS. 8 and 9), a wire-basketactuation assembly 113, and a Y-port 115.

Feeding tube 103 may be an elongated, flexible, tubular member made, forexample, of a suitable medical grade silicone, polyurethane or othersuitably flexible biocompatible polymer or structure. Feeding tube 103may have a uniform outer diameter along its entire length, except for anintermediate waist portion 124 of narrowed outer diameter, and may beshaped to include an internal end 121, an external end 123, a feedinglumen 125, an inflation lumen 127 and a plurality of wire lumina 129.Feeding lumen 125, which may be considerably greater in diameter thaninflation lumen 127 and wire lumina 129, may be centrally disposed andmay extend longitudinally between internal end 121 and external end 123.Inflation lumen 127 and wire lumina 129 may not be present inintermediate waist portion 124 but elsewhere extend parallel to feedinglumen 125 and be spaced around the periphery of feeding lumen 125. Wirelumina 129 may be equidistantly spaced apart from one another.

External bolster 105 may be a flexible, unitary member made, forexample, of a suitable medical grade silicone, polyurethane or othersuitably flexible biocompatible polymer or structure. In the presentembodiment, external bolster 105 may be a generally disc-shapedstructure having a central opening 130 into which tube 103 is insertedand may be securely retained by a friction-fit; however, it should beunderstood that external bolster 105 could be replaced with a variety ofdifferent types of external bolsters, including many types ofconventional external bolsters, without departing from the presentinvention.

End cap 107, which may be a unitary structure made, for example, of asuitable medical grade silicone, polyurethane or other suitably flexiblebiocompatible polymer or structure, may be fixedly mounted on internalend 121 of feeding tube 103. End cap 107 may comprise an end wall 132,end wall 132 sealing the internal ends of inflation lumen 127 and wirelumina 129. (Alternatively, this could be done with melting, therebyobviating the need for end cap 107.) A transverse opening 133 may beprovided in end wall 132, opening 133 being aligned with feeding lumen125 and matching lumen 125 in diameter so that the contents of lumen 125may flow freely through the internal end of lumen 125.

Balloon bolster 109 may comprise a flexible sleeve 141. Sleeve 141,which may be made, for example, of a suitable medical grade silicone,polyurethane or other suitably flexible biocompatible polymer orstructure, may be appropriately dimensioned to fit tightly over tube103, with the internal end 143 of sleeve 141 and the external end 145 ofsleeve 141 being securely bonded to tube 103 by a suitable adhesive 147and with the intermediate portion of sleeve 141, which is not bonded totube 103, extending over intermediate waist portion 124 of tube 103. Inthis manner, sleeve 141 may be expanded like a conventional balloonbolster by the introduction of fluids passing from inflation lumen 127through waist portion 124 and against sleeve 141.

Wire-basket bolster 111 may comprise a plurality of flexible wires, forexample, wires 151-1 through 151-4, each of wires 151-1 through 151-4preferably being a braided wire, more preferably being a braided wiremade of a material having shape-memory, elastic or super-elasticproperties. For example, nitinol may be used to form wires 151-1 through151-4; alternatively, other suitable metals, polymers or combinationsmay be used. It should be noted that the invention is not limited to thenumber of flexible wires that may comprise bolster 111. Each wire 151may extend entirely through a corresponding wire lumen 129, with theinternal ends of wires 151 being fixed to end wall 132 of end cap 107and the external ends of wires 151 being bundled together and fixed towire basket actuation assembly 113. In this manner, when wire-basketactuation assembly 113 is moved in the direction of end cap 107, wires151 are forced to bow outwardly through intermediate waist portion 124,thereby forming a wire-basket bolster. Thereafter, when wire-basketactuation assembly 113 is moved away from end cap 107, wires 151 returnto their straightened states. (By making wires 151 from a materialhaving shape-memory properties, one can bias the return of wires 151 totheir straightened states.) In some embodiments, the flexible wires maycomprise metals, polymers or combinations thereof. If desired, wires 151may be made to expand at body temperature or may be made to be biasedtowards a naturally bowed shape. In either case, the wires could bestraightened out by withdrawal of the device.

Wire-basket actuation assembly 113 may comprise a fitting 161 and anelongated tube 163. Fitting 161, which may be a rigid tubular structurepreferably made of a medical grade plastic, may be shaped to include abarb 165 and a longitudinal lumen 167, barb 165 being appropriatelydimensioned to fix fitting 161 within tube 163 by a friction-fit. Theexternal ends of wires 151 may be coupled together in a bundle 168,bundle 168 being fixed to lumen 167 by a suitable adhesive (not shown).(Instead of being bundled together in the manner shown, the externalends of wires 151 could be connected around the inner circumference oflumen 167 or could be secured to a ring that is, in turn, attached tothe inside of lumen 167 or embedded within fitting 161.) Lumen 167 maybe appropriately dimensioned to receive external end 123 of tube 103 bya friction-fit. Accordingly, when one wishes to expand wire-basketbolster 111, one may simply slide tube 163 towards tube 103 until tube103 is securely received in fitting 161. Thereafter, to returnwire-basket bolster 111 to its unexpanded state, one may pull tube 163away from tube 103 until tube 103 is removed from fitting 161 and wires151 straighten.

Y-port 115 may comprise a feeding port 171, an inflation port 173, aplug 175 and a barbed fitting 177. Feeding port 171 may include afeeding lumen 181, feeding lumen 181 being adapted to receive a feedingtip (not shown) of a conventional device used to dispense food and/ormedications into a PEG device. An anti-reflux valve 183, which, in thepresent embodiment, may be an integrally formed duckbill valve, may bedisposed within lumen 181 and may be appropriately positionedtherewithin to be opened by the full insertion of a feeding tip intolumen 181. Inflation port 173 may include an inflation lumen 185. Acheck valve 187, which may be identical in construction to the checkvalve of assembly 11, may be disposed within inflation lumen 185. Plug175, which may be tethered to feeding port 173 by a flexible strap 189or the like, may be appropriately sized to sealably, yet removably, fitinto the external end of feeding lumen 181. Barbed fitting 177, whichmay have separate lumina (not shown) aligned with feeding lumen 181 andinflation lumen 185, may be received, by a friction-fit, for example,within the external end of tube 163. Other fixture methods known in theart are conceivable, such as a screw-fit, snap-fit, etc. A small tube191 may be inserted at one end in the inflation lumen of barbed fitting177 and at the other end in inflation lumen 127 of tube 103. In thismanner, inflation fluids may be kept separate from feeding materials.

To implant assembly 101 in a patient, one may begin with balloon bolster109 and wire-basket bolster 111 in their unexpanded states (see FIGS. 7,8 and 10) and then may insert into the patient via an existing stoma theinternal end of assembly 101, with further insertion of assembly 101being limited by external bolster 105. Next, one may connect a syringeto inflation port 173 and may dispense a fluid (preferably a liquid,such as saline solution or sterile water) into inflation lumen 185 untilinflation bolster 109 is expanded to a desired extent. One then mayremove the syringe from inflation port 173. Next, one may expandwire-basket bolster 111 by sliding tube 163 towards tube 103 until tube103 is securely received in fitting 161 (see FIG. 9).

As can be appreciated, because of the presence of wire-basket bolster111, if balloon bolster 109 fails, the internal end of assembly 101 isstill retained within a patient while the patient seeks medicaltreatment.

It should be noted that, although, in the present embodiment,wire-basket bolster 111, when expanded, does not contact the radiallyinside surface of balloon bolster 109, wire-basket bolster 111 could beso modified.

Once assembly 101 has been implanted in a patient in the above manner,one may deliver food and/or medications to the patient through feedingport 171 in the conventional manner. When feeding port 171 is not inuse, one preferably seals feeding port 171 with plug 175.

To remove assembly 101 from a patient, one may pull tube 163 away fromtube 103 until tube 103 is removed from fitting 161 and wires 151straighten, thereby returning wire-basket bolster 111 to its unexpandedstate. Then, one may connect a syringe or the like to feeding port 171and withdraw a sufficient quantity of fluid from within bolster 109until bolster 109 shrinks to a sufficiently compact size to permit thewithdrawal of assembly 101 from the patient.

It should be understood that, although assembly 101 has been describedherein as a replacement PEG device, assembly 101 is not limited togastric applications nor is it limited to feeding applications.Moreover, assembly 101 is not limited to use as replacement device andmay be used as an initial placement device. Furthermore, assembly 101may be modified to be a low-profile device, instead of astandard-profile device, without departing from the present invention.

It should also be understood that, although wires 151-1 through 151-4run parallel to lumen 125, wires 151-1 through 151-4 could be helicallywrapped around lumen 125 or could be replaced with a single helicalcoil. Also, although wires 151-1 through 151-4 have a generally uniformcross-section along their respective lengths, wires 151-1 through 151-4could change in cross-section to optimize the strength of the wirestructure.

Actuation of wire-basket bolster 111 is not limited to placement of theproximal tube. It may, for example, be actuated by a separate slidingrod or tube to push down on wires 151-1 through 151-4. It may beactuated by twisting tubes. It may be actuated by inflation of theballoon bolster, which could expand the basket and lock the wires inplace (there also being an unlocking mechanism). It may also be actuatedwith a pull wire to compress the tube.

In another embodiment (not shown), wire-basket bolster 111 may bereplaced with a second balloon bolster. Such a second balloon bolstermay require a second inflation lumen and second inflation port. Such asecond bolster would be situated inside of first bolster although it maybe situated proximally or distally thereof as well. In still anotherembodiment (not shown), wire-basket bolster 111 may be replaced with amalecot bolster.

The embodiments of the present invention recited herein are intended tobe merely exemplary and those skilled in the art will be able to makenumerous variations and modifications to it without departing from thespirit of the present invention. All such variations and modificationsare intended to be within the scope of the present invention.

1. A medical catheter assembly, the medical catheter assemblycomprising: (a) a feeding tube having a proximal end, a distal end, anda longitudinal axis; (b) an internal expandable bolster disposedproximal to the distal end of the feeding tube such that the distal endof the catheter extends past the bolster when the bolster is expanded,the internal expandable bolster comprising a first expandable structureand a second expandable structure, said first expandable structurecomprising a balloon, and said second expandable structure embedded inthe balloon adapted to remain expanded in the event of a balloonrupture; and (c) an external bolster disposed at the proximal end of thefeeding tube, said external bolster comprising an inflation port and afeeding port.
 2. The medical catheter assembly as claimed in claim 1wherein the second expandable structure has sufficient flexibility tobend as the balloon expands and contracts and yet has sufficientrigidity to maintain a bent shape if the balloon breaks.
 3. The medicalcatheter assembly as claimed in claim 1 wherein the second expandablestructure comprises at least one of at least one linear reinforcingstay, at least one circumferential reinforcing member, at least onehelical coil, and at least one expandable wire mesh tube.
 4. The medicalcatheter assembly as claimed in claim 3 wherein the second expandablestructure comprises at least one linear reinforcing stay.
 5. The medicalcatheter assembly as claimed in claim 3 wherein the second expandablestructure comprises at least one circumferential reinforcing member. 6.The medical catheter assembly as claimed in claim 3 wherein the secondexpandable structure comprises at least one helical coil.
 7. The medicalcatheter assembly as claimed in claim 3 wherein the second expandablestructure comprises at least one expandable wire mesh tube.
 8. Themedical catheter assembly as claimed in claim 1 wherein the feeding tubehas two lumina, one of the lumina being an inflation lumen for use ininflating the balloon.
 9. The medical catheter assembly as claimed inclaim 8 wherein the feeding tube is a gastrostomy feeding tube adaptedto extend through the abdominal wall.
 10. A medical catheter assembly,the medical catheter assembly comprising: (a) a medical catheter havinga proximal end, a distal end, and a longitudinal axis; (b) a firstexpandable bolster disposed at a distal end of the medical catheter,wherein said first expandable bolster comprises a balloon bolster; and(c) a second expandable bolster disposed within an inner surface of thefirst expandable bolster, wherein the second expandable bolstercomprises a wire-basket bolster, said wire basket bolster comprising aplurality of wires.
 11. The medical catheter assembly as claimed inclaim 10 wherein each of the wires comprises a shape-memory orsuperelastic or elastic material biased towards a naturally straightenedstate.
 12. The medical catheter assembly as claimed in 10 wherein themedical catheter is a feeding tube adapted to extend through theabdominal wall.
 13. The medical catheter assembly as claimed in 10wherein the medical catheter is a gastrostomy feeding tube adapted toextend through the abdominal wall.
 14. The medical catheter assembly asclaimed in claim 1, wherein the second expandable structure is made ofmetals, polymeric materials, elastomeric materials, or combinationsthereof.
 15. The medical catheter assembly as claimed in claim 10,wherein each of the plurality of wires extends through a wire lumen. 16.The medical catheter assembly as claimed in claim 10, wherein a distalend of each of the plurality of wires is connected to an end cap on thedistal end of the catheter.
 17. The medical catheter assembly as claimedin claim 10, wherein a proximal end of each of the plurality of wires isconnected to a wire basket actuation assembly.
 18. The medical catheterassembly as claimed in claim 10, further comprising an external bolsterdisposed at the proximal end of the catheter.
 19. The medical catheterassembly as claimed in claim 10, wherein the first expandable bolster isnot configured for delivery of fluids through the wall of the bolster.20. The medical catheter assembly as claimed in claim 10, wherein thefirst expandable bolster is substantially non-porous.
 21. The medicalcatheter assembly as claimed in claim 1, wherein the internal expandablebolster comprises a compliant material.
 22. A medical catheter assembly,the medical catheter assembly comprising: (a) a feeding tube having aproximal end, a distal end, and a longitudinal axis; (b) an internalexpandable bolster disposed proximal to the distal end of the feedingtube such that the distal end of the catheter extends past the bolsterwhen the bolster is expanded, the internal expandable bolster comprisinga balloon and an expandable means for retaining the feeding tube inposition in the event of a balloon rupture, wherein the expandable meansis embedded in the balloon or located within the balloon; and (c) anexternal bolster disposed at the proximal end of the feeding tube, saidexternal bolster comprising an inflation port and a feeding port. 23.The medical catheter assembly as claimed in claim 1, wherein the wiresare made of a metal material.